Power generation from veratryl alcohol and microbial community analysis in the microbial fuel cell

Abstract

Veratryl alcohol (VA) is a product from the biodegradation of lignocellulosic biomass. The objective of this study was to explore the possibility whether VA could be used as the fuel of the microbial fuel cell (MFC) to generate power. Two types of MFCs, a two-chamber MFC and a single-chamber air-cathode MFC, were set up for experiments. In the two-chamber MFC, average maximum current outputs higher than 700 μA were obtained using various mixtures of glucose and VA as the fuel. The highest power density of 35.17 W m−3 was achieved using the mixture of 1000 mg L−1 glucose and 50 mg L−1 VA as the fuel. With 500 mg L−1 VA as the fuel in the MFC, we obtained an average maximum current output of 181 μA. In the single-chamber MFC, the maximum current output reached up to 178 μA with 500 mg L−1 VA in the fed-batch mode and the maximum CE reached 23.77% with 100 mg L−1 VA. At the end of all operation cycles of the MFCs, the glucose and VA were undetectable in the solution, and the removal efficiencies of COD were between 75% and 88%. The denaturing gradient gel electrophoresis profiles of 16S rRNA gene indicated that the dominant species on the anode biofilm did not change significantly with the different substrates, but the abundance of some species increased greatly. The scanning electron micrographs showed that the most abundant bacteria on the electrode were bacilli. The dominant species belonged to bacteroidetes and proteobacterium.